Multipoint, virtual control, and force based touch screen applications

ABSTRACT

A method and apparatus are provided providing a touch screen having multipoint sensing and/or force based sensing and feedback capability useful in many applications which extend beyond traditional computer applications. The touch screen can be located in many non-traditional locations as well, such as desks, tables, walls, vehicles, and the like. The apparatus may be used by a single user, or multiple users, employing fingers, hands, feet and other body portions, if desired or practical. Related applications for virtual image or physical control applications are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/495,666filed Jul. 31, 2006, now U.S. Pat. No. 7,714,849; which is acontinuation of application Ser. No. 09/435,854 filed Nov. 8, 1999, nowU.S. Pat. No. 7,098,891; which is a continuation of application Ser. No.08/496,908 filed Jun. 29, 1995, now U.S. Pat. No. 5,982,352. All ofthese prior applications are hereby incorporated by reference.

The disclosures of the following U.S. patents and patent applicationsare also incorporated herein by reference:

U.S. Pat. No. 4,629,319 (“D-SIGHT”)

U.S. Pat. No. 4,394,683 (“Circuits”)

U.S. Pat. No. 4,373,804 (“Turbine”)

U.S. Ser. No. 08/290,516 filed Aug. 15, 1994 (“Man Machine Interface”)

U.S. Ser. No. 08/203,603, filed Feb. 28, 1994 (“Robot Vision UsingTarget Holes . . . ”)

U.S. Ser. No. 07/664,574, filed Mar. 6, 1991 (“Targets II”)

U.S. Ser. No. 07/875,282, filed Apr. 29, 1992 (“Vision Target BasedAssembly”)

U.S. Ser. No. 08/161,304, filed Dec. 2, 1993 (“Controlled Machining”)

INTRODUCTION

The invention disclosed herein is a new type of data entry device forcomputers and other electronic equipment generally in the category ofdigitizers and touch screens having several unique properties. It isbased primarily on the electro-optical determination of temporarysurface distortion caused by the physical input signal, or force,creating the distortion (e.g. a finger “touch”). This is herein referredto as surface distortion imaging and depends on the ability to detect,and in some cases quantify, small distortions of a surface over a large(by comparison) area.

A preferred means of detecting surface distortion is that given inreference 1, which discloses illumination of a surface and subsequentretroreflective re-illumination of the surface from which an enhancedimage of the distortion in such surface are created. This method (andthe products based thereon sold under the trade name “D-SIGHT™”), is atonce, simple, fast, and capable of intelligibly measuring minutedistortions over large surface areas. All of these are advantages forthe present disclosed invention, and D-SIGHT™ is the preferred method(but not the only method) for determining such distortions. Otheroptical techniques are grid and moire triangulation, also providingsurface distortion data.

Distortion in a material (rather than a surface thereof), canalternatively be used, detected by schlieren, transmissive D-SIGHT, andin photoelastic stress based techniques, relying on stress relateddifferential refraction in the material, rather than deflection of thesurface. In both cases video cameras scanning the image of the area ofthe material or surface are the preferred transduction device

Also disclosed herein are novel means to determine other events whichcooperatively or individually may a be imputed to a computer by means ofthe invention. These particularly concern electro-optically determinabledatums on persons or other entry means.

REVIEW OF THE PRIOR ART

The typical data entry device for a computer to date, has been akeyboard. More recently the “mouse” and “joy stick” have been devised toallow entry of data and particularly picture type data, onto a computerscreen.

Tracing tablets (digitizers) have been derived using varioustechnologies for indicating for example, the X, Y location of a pencilstylus, using ultrasonic, inductive or other means.

In addition to the above, such data entry can be combined with a displayin a product commonly known as a “touch screen”. In this product, datais presented on a TV screen and the human can touch certain boxestypically which have been encoded on the screen to register his inputdata choice.

In regard to touch screens, these are generally categorized as beingeither of the non-contact beam-break type usually using multiple lightsources or, a type employing multi layer overlays using optical,acoustic, or capacitive phenomenon to determine a location of thetouching member.

A brief review of the prior art relative to touch screen technology isgiven in U.S. Pat. No. 4,675,569 by Bowman. Bowman discloses a touchscreen technology using a bezel with piezo-electric elements at the fourcorners which, upon being stressed by a touch on a glass faceplate forexample, creates force signals which can be used to decipher the X,Ylocation of the pressed point. Presumably this technology could also beused for determination of 3-D force variables as well.

Disadvantages of previous touch screens which are purported to beovercome in part at least by the Bowman invention, are accuracy, shock,wear, reliability and electro magnetic radiation.

Other prior art technology (Touch screen or digitizer) relates tocapacitive devices in which one plate is pressed closer to another at adifferent point and related by a grid scan mechanism and to scannedcontact types wherein a grid scan mechanism and to scanned contact typeswherein a grid of conductors (either fiber optic or electrical), arecaused to be contacted at one point which again can be scanned out.

Other touch screen technology (U.S. Pat. No. 4,700,176) uses surfacewaves induced in a material which are damped at a given location inspace due to the touching arrangement. U.S. Pat. No. 4,740,781 describeconductive film based touch screens. U.S. Pat. No. 4,710,758 addressesthe problem of calibration of all touch screens, particularly a problemfor those based on analog principles. Problems of electro magneticshielding of touch screens which can be a problem in secure environmentsare addressed, for example, in U.S. Pat. Nos. 4,692,809 and 4,591,710.

Where one admits to a conductive stylus or other special writinginstrument, then higher resolution transmissive digitizing screens canbe contemplated such as that of U.S. Pat. No. 4,639,720. Other“digitizers” not incorporating a screen display are represented by U.S.Pat. No. 3,692,936 describing an acoustic digitizer pad, U.S. Pat. No.4,177,354 describing a digitizer with a light responsive grid, and U.S.Pat. No. 4,255,617 describing a digitizer with a capacitive grid.

U.S. Pat. No. 4,736,191 describes a digitizer pad which is a type ofdigitizer capable of providing a X,Y and Z axis indication proportionalto the area of touch, a third dimension of sorts.

No known prior art exists in the area of data entry devices based, likethe instant invention, on optical surface distortion measurement.

In general, it can be said that all of these prior art devices typicallyare one or two dimensional, that is, they either register a singlecommand as in a typewriter key or the XY location of a command as forexample a light pen location on a screen or a stylus point, etc. It istherefore very desirable to have a three dimensional capability, capableof registering not only the X and Y but also the Z value of a force ordisplacement caused by a particular entry command. No known commercialdevices can do this, and a limited technology set exists for thispurpose—especially over large extensive screen or pad areas.

In addition, conventional technologies typically limit the resolution orthe size or both of the display to which entry could be made. Forexample, touch screen data entry is commonly available over a standardlet us say 12″ to 19″ computer terminal to the level of 1 part in 40 inboth X and Y. While this suffices for many computer data entry purposes(e.g. selecting icons), it is certainly not suitable for high resolutiondrawing on a screen or other such activities. Prior art is lacking whichcan accommodate high resolution “touch” or other inputs easily overlarge surfaces such as for example data displays in military war roomsand the like. In addition, high resolution seems possible in prior artdigitizers only by moving special apparatus or using special writinginstruments such as a conductive pen, and high resolution touch screensare difficult with digital technologies such as the discrete grids. Suchgrids also run the risk of degrading the light transmissioncharacteristics of the screen.

Another drawback of most conventional data entry systems today is thatthey can only respond to one point at a time. In other words, a singlefinger on the screen, a single mouse location, a single joy stick entry,a single key on a keyboard. In many applications it would be desirableto be able to enter more than one point at a time or rock back and forthbetween two points or the like. Indeed it may be desirable to enter notjust points but a complete “signature” as in a hand print or theequivalent. This is very useful for recognizing inputs from disablepersons, or as a means of verifying authenticity.

Accuracy is also a problem with most digitizers and touch screens, inparticular those using analog principles (e.g. the Bowman referenceabove). Indeed for those digitizers and touch screens based for low costor other reasons on analog transduction technologies, calibration isoften required. One implication is that icon size on the screen must belarge, if calibration can't be maintained.

There is virtually no evidence of 3-D capability in the finger touchdevices. The closest art found is that of capacitive change in area dueto contact with the touch panel.

One prior art device (U.S. Pat. No. 4,639,720) describes an importantcapability of drawing directly on the screen with commonly used oravailable instrument (e.g. a pencil). This is a key item in aman-machine interface equation, getting away from the artifice ofdrawing pictures with a mouse let us say while looking at the screen(the technology disclosed herein also allows one to draw on the screendirectly).

ADVANTAGES OF THE INVENTION

The disclosed invention at one and the same time obviates thedifficulties above in a manner that is also cost effective. In addition,it contains several unique advantages not known to exist elsewhere,viz.;

1. A potential “four” and “five dimensional” capability, wherein theforce vector direction as well as the magnitude of force is measured.

2. An ability to detect dynamic events over a very large area, also withtemporary data storage.

3. An ability to have a data storage of a complete signature at once,physically or in memory. The invention has a unique dynamic detectionability due to its image storage capability. No dynamic event detectionis apparent in the prior art, and few prior art touch screens, evenappear capable of transient or dynamic operation. The invention on theother hand can be used with strobed light sources which can be triggeredto capture fast transient events. Even when successive readings arerequired, several thousand readings a second can be obtained of thecomplete surface. Transient events can be stored by the image capturemedium and in some cases can be actually stored by the sensing surfaceif it has a hysteresis “memory”. This allows it to be used for dynamic“hits” such as those of projectiles on the screen, not just continuoustouches.

4. An ability to have the surface distortion or touching input means ofany material, completely removed from the actual sensing of the input.Specialized capacitive screens and the like are not required. However,an LCD display screen can for example, be used to form a portion of thesurface.

5. In addition, the invention is extremely cost competitive to othertouch screen or data entry techniques—particularly for larger surfaces.(For example, one meter square and larger.) The resolution obtainable inthese larger surfaces is unmatched, being capable with today'stechnology, of reaching greater than one part in 10,000 in eachdirection of the surface (100 million resolvable points on the surface).

6. Unlike most other types of displays, several embodiments of thedisclosed invention give a desirable tactile feedback since it is theactual physical deformation (and the amount thereof) that is responsive.Thus the feedback to a finger (or other member) in terms of resistiveforce is proportional to the desired input. This tactile feedback isparticularly desirable in for example the automobile where one shouldnot take one's eyes off the road.

7. Another advantage of the disclosed invention is that it can create atouch screen data entry of very high resolution with such entry madedirectly on the screen (not on a special pad, as in most CAD systems)with the “beam” of the CRT or other type of display literally followingthe touch point just as a pencil line would follow a pencil. In thisapplication the 3-D capability allows one to press harder and make adarker (or wider) line for example, just as one would do in normalpractice.

The capability of the invention to be ergonomically and “naturally”compatible with human data entry is a major feature of the invention.

8. The reliability of some of the touch screen prior art isquestionable. Capacitive devices in close contact are subject to wear,humidity, electric fields and other variables for example. In addition,many prior art touch screens are of specialized construction and wouldbe quite expensive to replace if they were broken, especially as thesize increases. In the case of the invention, sensing of the screen isnon contact, and the sensing screen can be as simple as a piece of plateglass, or a wall.

Many touch screen designs appear to have problems connected with electromagnetic radiation and can pose a problem in high security areas. Thisproblem does not exist with the disclosed invention.

9. Multipoint Operation. Many of the existing touch screen prior art arecapable only of measuring one touch point in X and Y at a time. Whilesome other prior art designs would not appear to preclude multi-pointsimultaneous measurement, none apparently is disclosed. The invention iseasily capable of multi-point operation or even detection of complexarea “signatures” not just “points”.

As an example of the multi-point difficulties with the prior art, thelight curtain type non-contact touch screens clearly have an obscurationproblem, as the finger indicating one point obscures the view ofanother.

10. Reflection and Transmission. The invention, unlike most of the priorart, can be used both in reflection and for transmission measurement ofdeformation. The camera system used in the device can be used for otherpurposes as when and indeed the touch screen or digitizing systemdisclosed can be used simultaneously with prior art systems for acombination effect if desired.

A further advantage of the inventions ability to detect multiple inputsignatures, etc. at any point on its face, therefore a keyboard, a pianokeyboard, a joy stick can be artificially created at any point undercomputer control or simply by random human command. This is a particulardesirability in a car where you cannot necessarily keep your eye on thedata entry device or for example for handicapped people who could not beexpected to hit the right point on the device every time, but if theyjust hit the device anywhere, could make a move from that point in amanner that would be intelligible to a computer for example.

11. Common Systems. In addition to the above advantages over the priorart, the invention also has an advantage that it employs essentiallystandard hardware for any screen size. The same technology is applicablefor a screen or “pad” of say 3″×4″ (8×10 cm) such as might be in a cardashboard all the way to screens or digitizers; the size of a wall. Thisallows the cost to be reduced as the technology can be shared.

12. Variable and “Intelligent” orientation. It is also useful thereforeto replace in many cases keyboards which have continuous arrays of keys,be they optical, mechanical, contact, electro mechanical or whatever.Unlike most keyboards the disclosed type can “float” (i.e. be at anyzone on the surface) which is convenient for people who know how to typebut cannot see the keys for example, while driving.

13. Tactile feedback, including programmable. The unique tactilefeedback application aspect of the invention allows one to essentiallyuse a deformable member as a sort of miniature joy stick for each fingeror to rock back and forth between one or more fingers to createdifferent signals. In addition, programmable tactile feedback such asair blasts, vibration, etc., can also be added easily to the touchsurface.

14. Another advantage of the invention is that it can detect a force ordisplacement signature such as of an object that would be picked up by arobot hand. Of interest as well is the ability to sense the signature ofsomeone, even one who would enter a signature of his palm or what haveyou. This may be of considerable use to the blind and other physicallydisabled persons, allowing use of non-conventional inputs (e.g. elbowstoes, etc) and the tactile feedback afforded is particularly helpfulhere.

15. In a gaming and simulation context, the invention has the advantagethat it is low in cost, and provides a method by which the game playercan participate in a physical way, just as in real sports, and the like.

Further disclosed in this invention is a variation on the invention foruse where inputs other than physical touching are used to temporarilydeform the medium. This can be TV, thermal, air, vacuum,electro-magnetic—or any other physical force which can temporarilyeither distort the surface in any direction.

The ability of the invention to detect temporary distortions also leadsit to be usable over broad areas for unique transduction applicationssuch as weighing trucks on the highway “on the fly”, counting lumps ofcoal on a specialized conveyor belt, counting/weighing and other suchapplications, or in any other application where transient deflectionsare the desired signal.

These and other advantages of the invention will become clear in thefollowing disclosure which is depicted in the following figures.

Summary of Advantages To conclude, the invention disclosed herein hasnumerous advantages, for example:

1. 3-D MYX capability, plus an additional 2-D of vector input.

2. Simplicity and Low cost, particularly for large area applications.

3. Multi-point, and area signature capability, also with simultaneousdetection

4. Non-contact sensing of screen deformation due to “touch”—wear freeand reliable

5. Excellent dynamic detection of both transients and repeating inputs

6. High accuracy—all digital sensing, no analog calibration required

7. Achievable resolution 1/10,000 in both X & Y, via sub pixeldigitization 8. Screen/plate material independent. For example, cangenerate a surface response on program command, or use transparent mediasuch as rear projection screens.

9. Commonality—all screen or pad sizes can use substantially the samehardware

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will further be described in the following figures:

FIG. 1 is a prior art touch screen or digitizer having conducting barsin an orthogonal grid.

FIG. 2 is a basic embodiment of the invention in touch screen formutilized with a projection TV (front or rear), and employing a D-SIGHTtransduction of surface distortion.

FIG. 3 illustrates sensing of force (displacement) vectors using theFIG. 2 device, and includes a hand print evaluation aspect of use to thehandicapped.

FIG. 4 illustrates a block diagram of one embodiment of the invention

FIG. 5 illustrates a combined system employing a target trackingembodiment of the invention and touch screen embodiment similar to FIG.2 for use with projectiles.

FIG. 6 illustrates a multipoint, or signature version of the invention,in a virtual environment situation. Also illustrated is the use of gridprojection triangulation for surface distortion analysis, and amulti-segment version of the invention

FIG. 7 illustrates a “digitizer” pad embodiment of the invention used asan automotive dashboard input, further incorporating tactile feedbackcues, both passive and active, via piezo vibrators, air blasts, soundwaves, or the like.

FIG. 8 illustrates a force field (electromagnetic, sound, or other)embodiment of the invention, using a moire grid transduction of surfacedistortion

FIGS. 9 a and 9 b illustrate transmission and photoelastic variants ofthe invention. Also illustrated is a photoelastic based sensing of forcelocation due to stress.

FIG. 10 illustrates further the use of the invention for dynamicprojectile detection, and methods thereof used in a single ormultiperson sports gaming simulator embodiment designed for sports barsor home use.

FIG. 11 is a D-SIGHT primary image embodiment of the invention

FIG. 12 is a Multiple simulator application type panel, includingprogrammable knob or other features, and overlays using the multi pointand tactile advantage of the invention

FIG. 13 is and additional overlay embodiment of the invention

FIG. 14 is an embodiment of the invention having deforming bladders fortouch and feel.

FIG. 15 illustrates a stereoscopic deflection determination, andcorrection matrix for the screen of the invention. Also illustrated isthe case in which the screen is locally distorted so as to impact thelight transmission or reflection from the screen from external sourcesnot used in the TV display function.

FIG. 16 is a screen location calibration system of the invention

FIG. 17 illustrates a non optical embodiment for screen deflectiondetermination—in this case radar based, which is optionally oralternatively capable of seeing an thrown object.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1

A typical prior art touch screen arrangement which, like the invention,operates in a physical touching mode, is shown in FIG. 1. In thisarrangement, a transparent member 12 comprised of a periodic set ofconductive bars is placed on the front of CRT tube 10. It is opposed bya second member 13, whose surface includes a set of conducting bars inthe orthogonal direction. The two conducting surfaces are separated by athird transparent insulating medium 15, having on array of holes in itwhich can allow the force of touching to push the front surface throughto the rear surface thereby making contact. By scanning the conductorselectronically, at the point of contact, a signal is generated whichthen gives the XY location on the screen of the touch.

The resolution of the conventional touch screen technology representedby FIG. 1 is limited in that the horizontal/vertical lines must be wideenough spaced so that one can push through without touching adjacentones. In addition, both the transduction medium and the separatormaterial, is worn during operation of the device, which can also beaffected by humidity, and strong electric fields.

In contrast, the disclosed invention uses a single screen element anddoes not require overlays on top of an existing screen. LCD flatdisplays and projection TV can be directly be used. Conversely however,it is generally difficult to use the invention with conventional CRTbased TV tubes without substantial modification (especially in regard tothe heavy faceplate).

FIG. 2

Consider the operation of FIG. 2, which illustrates the basic embodimentof the invention in its touch screen and data entry “digitizer” form.

A projection TV (such as one may buy in the stores today and typicallywith a 50″ diagonal screen size), 100, is principally comprised of ascreen 101 which is illuminated by a projection TV assembly 110, knownin the art, comprised of 3 electron guns, red, green, blue, each with acorresponding lens which images the face of the tubes onto the screen101 in registration, that is, so each of green, blue and red images ofthe scene commanded by control 120, are overlaid upon one another so asto be able to produce the colors desired with appropriate inputs to theguns.

A viewer 150, looks at the image diffused from the rear projection ofthe TV onto the screen. For purposes of the invention, the screen 101has a substantially flat rear surface 102. This arrangement iscommercially available.

The goal of the invention is to optically determine the location (and insome cases magnitude and direction as well) of one or more localdistortions 103, of the screen, 101 manifested on rear surface 102 uponinput of one or more deflecting forces F (as from a finger) whichdeflects the screen. The optical determination is accomplishedpreferably by TV camera 160 whose field of view generally covers asubstantial portion of surface 102. Visible, IR, UV or any otherwavelength of radiation which can be seen by the camera (which could bean IR TV camera for example) is used as the illumination source. Thescreen can be plain, or have writing or designs on it in certain areaswhere, for example, input of a certain type is desired.

The preferred method of determining screen deformation shown in thisembodiment, is to use the D-SIGHT™ principle described in theaforementioned U.S. patent (ref 1). In this example light source 170illuminates the rear smooth portion 102 of the screen 101 and light fromthat smooth portion is reflected to retroreflector material 171(typically Scotchlight 7615 glass beaded material by 3M company) whichthen re-reflects it to the surface 102 and thence to TV camera 160.

The light source 170 can be located off the axis of the TV camera lensas shown, which creates a unique contour type “D-SIGHT image”, providinga shading effect of any distortion present which indicates thedirection, magnitude and shape of the distorted portion of the surface.Alternatively however the light source can be located essentially on theaxis of the camera often (through use of a beam splitter or otherwise)and in which case the TV camera input detects a dark zone when thescreen is pushed in by the action of the force (e.g. a finger “touch”).Detection of these types of images in the context of this application isfurther described below.

For example, in pressing on back of painted steel 50 inches square and0.030″ thick secured on its edges, one can see effect of finger movingrapidly, and can see “Z” deformation local to ones finger by theincreasing image darkness and spot size at the finger point The effectseems reasonably localized size of indication about size 0.5 inch indiameter as seen on TV screen display of the D-SIGHT image of the steelsheet. At edge of panel near point of support on edges panel stronger,didn't deflect near as much.

Rubber and latex provide extremely local surface deformation But latexas a writing pad is not be as nice as steel, plastic or glass with ahard surface. To improve screen or pad material properties, compositematerial combinations can be used, e.g. Rubber impregnated plastic, thinglass or plastic sheets with transparent stiffeners, etc.

To operate the invention, the camera is typically scanned out at normalTV frame rates 30 times or 60 times a second, and the determination ofthe XY location of the force input determined from the centroid of thedeflected disturbed light energy. This detection is accomplished ineither hardware or software. In the simplest “On-Axis” case (where thelight source and camera are effectively co-axial), the centroid “C” in Xand Y of dark energy, 200, shown in the representation 201 of theon-axis D-SIGHT image of surface 102, is detected. The methods foraccomplishing this detection and for providing, if desired, real timeoutputs, that is, every frame rate, are described in detail in U.S.patents of reference 2, which utilize the detection of the first orsecond derivative, the moment, or the average light intensity centroidfor example.

The XY coordinates are easily determined by finding the XY centroidlocation. This can typically be done to resolutions less than the actualpixel spacing on the camera array with 1/10 of a pixel being commonplaceas described in the references. In this case we could see that for a1000×1000 array, the sensitivity in XY direction can be 1 part in 10,000of the screen field—e.g. 0.1 mm (0.004″) on a 1 meter square field.

To determine the Z value representing the deformation proportional toforce, the degree of darkness (or lightness) of the spot, (oralternately it's diameter or area for a given degree of darkness such asVthres or greater, say,) can be determined. For example indentation 205indicates a larger Z distortion, and thus force F, for a constantelastic property of the screen 101, typically of plastic or glass. Ifnot constant, it can be calibrated and a calibration table stored in thecomputer 185 to correct each reading. Not only is the area or diameterof light of intensity darker than dark threshold V, but the maximumvalue of darkness Vmax is higher as well. The harder one pushes, thedarker and bigger it gets.

It is noted that the invention can also be used in an alternative frontillumination mode as shown, monitoring screen deflection with lightsource 170 a, camera 160 a, and retroreflective screen 171 a, and/orfront projection of TV images on the screen with alternative projector110 a.

Also shown in this embodiment is another variation of the inventionusing a photoelastic technique, which has the advantage of beingresponsive to stresses induced in transparent media, and not todeflection per se, thus potentially allowing a stiffer member. In thisexample, the reflective stresses in a photoelastic material chosen tocomprise the screen in this case to 101 are determined by placing acoating 138 on the front of the screen (instead of placing the coatingthat might be used to render the screen more reflective at a certainwavelength to the light 170, on the back of the screen, one can place iton the front of the screen) such that the light from 170 has to passthrough the screen material twice. In this way, photoelastic changes inthe material can be viewed if the light is polarized as with polarizer144 and cross polarizer located in front of the camera 145 (also whererequired allowing for polarization rotation on reflection).

The screen 101 can be of any suitable material which can withstand theforce-F, and deflect proportionally thereto. Or it can be curved, aswell as flat, and be made up of individual cells rather than one pieceas shown. The system can operate with front or rear projection and front(or rear) screen distortion monitoring.

It is noted the viewer can wear LCD or other electrically shutterableglasses which allow alternate frames of stereoscopic TV projections toenter the eye, to recreate the stereo effect. Other stereo effectmethods such as alternate left right polarization or any other techniqueto provide stereo in conjunction with the invention can be used.

In this it is noted that a single television camera 160 with a 1000 by1000 pixel elements can be used to look at the deflecting surface 102.If more resolution is desired, more dense pixel cameras can be used orconversely multiple sets of cameras can be utilized, each one looking ata given portion of the surface with the results combined. It should benoted that where accuracy rather than resolution is required it isnecessary to calibrate the camera and optical system for the bestresults, using either known inputs or a grid pattern such as 168 placedon the surface which can be utilized to correlate surface points topoints in the image plane of the lens at the camera.

Applications

Now let's explore some of the applications of the invention depicted inthe above embodiment. Compared to the prior art, I feel the inventioncan produce much higher resolution on a large screen basis, at least inthe rear projection format. In addition, this resolution is digitaldepending in its primary manner on the digital fixed position of theindividual detectors (pixels) on the array chip. This means that it isintrinsically self calibrated and free from analog drift as common toother types of touch screens or digitizer technologies which claim highresolutions.

The invention is well suited for simulation such as in an arcade game orfor training simulations. The video inputs can be anything, includinginteractive video from disk where different scenes are called up as aresult of the input force, touch or hit. One can actually even projectin 3-D on the screen for the observer 150 equipped with special glasses(to view alternate stereoscopic images). One can have extremely realeffects where the human observer can in turn throw an object atsomething, hit it, shoot at the screen or whatever the input is desiredto interact with the video on the screen. With 3-D, the point ofperceived impact on the screen can be at, in front, or behind the screenitself, with appropriate compensation for same, in determining where theimpact would have been relative to the image.

The second major application is the use of the invention as a CAD designterminal where one could easily picture the embodiment of FIG. 2 tiltedon its side to present the screen at essentially a 45 or 30 degree angleto the horizontal and so usable in a drawing board format, such as 230.It can even be horizontal itself as in a desk top for that matter.Indeed, the cost of having such a device as a desk top needn't cost muchmore than $5000—television, desk, inputs and all. This puts it easilywithin the realm of executive desk top devices where literally the deskbecomes the viewing and input means.

In the case of a CAD entry, it can be with a touch or for more detailedentry, with any sort of stylus device as in a pencil such as 210. (withhighest resolutions-generally resulting from taut rubberized screens).In the 3-D context, the more one pushed on the drawing instrument,finger, pencil, pen or whatever, the darker a line could be if one wasactually drawing on it using it in a drawing mode.

For use as a digitizer or as a touch screen, the invention has a verydesirable tactile “feel” of it, i.e. it the more you push, the moreresistance your feel and the more it registers. This tactile feel willvary depending on the type of material chosen. While it is generallycontemplated that single membranes, at least over some portion of thetotal surface area would be utilized to keep the device simple andwatertight, etc. this might not need to be the case.

For example, a surface composed of links effectively hinged could beutilized much as one might think of smaller surface elements chainedtogether which could deflect as miniature plates about the hinge pointscould be utilized. They could be either chained together to form alarger overall membrane or they could be just simply hinged to simplesupports much like a present keyboard. In this particular issue which ismeasured with D-SIGHT™, it is not so much deflection of the “key” soproduced that causes the reading but a slope change for example due toan increasing slope caused by one pushing in on one of the “keys”.Another advantage of the FIG. 2 device is that it is responsive both tothe pressure of the finger in as well as any sort of force that wouldtend to pun the screen out. In this manner, it differs greatly fromalmost all other touch screen devices. While one cannot touch “out”, ingeneral, there are forces, the most obvious one being vacuum, that cantend to pull the screen material outward. These include electromagnetic, electrostatic, and thermally induced forces and the “two way”ability of the invention to register such an input is notable.

We should add that these concepts, while they've been shown in thecontext of a rear projection display device as in FIG. 2, are reallyquite usable in the context of the invention with any sort of displaydevice. For example, screen 101 could be a LCD device would not requireguns (and respective lenses) 110 for projection. It might be essentiallyself generating. Typically such LCD devices do require a fight sourcewhich could be located in the place of the guns to illuminate the LCD.Interestingly, the same light source 170 used for the readout of thescreen deflection, could even be the one that illuminates the LCD's,particularly if one was viewing at an angle. It should be noted that tokeep the light source 170 from being obtrusive to the observer, one maychoose an infrared light source such as infrared LED's (and if desired,a corresponding bandpass filter in front of camera 160). This makes thecamera 160 responsive only to the light from the light source 170 andconversely keeps the eye from being able to pick up any light that mayescape through the front of the screen from the light source 170.

In the CAD data mode, the position coming from the centroid detectionelectronics 185 connected to the camera, is shown in the flow blockdiagram to the gun control drive electronics 120 to if desired, allow anelectron beam in one or more colors to trace directly behind the contactpoint or in fact because of the speed of the device, within a 30th of asecond, to overlay the contact point. This allows one to actually followone's drawing right on the screen with the computer generated renderingthereof. Conversely, the human can trace on, or create, a TV image ifdesired. This ability to draw right on the screen is a major advantageof the invention. The scan of the CRT (or an equivalent projection unitsuch as a LCD light valve, or micromechanical multimirror device) tracesa point (and with suitable latency a line or image) to follow the pointdrawn by the user. A computerized rendering capability can be providedusing fill in to correspond to a human using a shading pencil, etc—acapability not available with any other touch screen technology knowntoday.

Even voice can be stored along with the rendered image. In using 3-Dstereo, one can compute the location in the interior which is beingdrawn and enter its coordinates

If one knows the timing of the touch or event, one can actually strobethe light source to catch this event precisely so that no blur exists.Conversely, one can also simply read the TV camera display at a certaintime as well since some TV camera frames can be read out as many as 2000frames a second (Kodak Ektographic TV camera) the actual registering ofdynamic inputs, etc. can be done.

It should be also noted that the camera unit does not require ingeneral, the calibration of the device. However, for odd viewing angles,special high accuracy considerations, etc., one can use a pre-calibratedscreen in which the Z direction inputs and/or XY locations are stored inmemory in an accurately calibrated manner. This is shown in the blockdiagram of FIG. 4 as an optional look up table for stored values.Alternatively, fitting of curves to data and other means to moreaccurately predict position can be used.

FIG. 3

Figure illustrates details of a system according to an invention for 3-DCAD drawing. In the application shown the person draws a picture whichis to be entered into the computer and in an embodiment actuallymodifies using his drawing project on the surface/screen by theprojection TV set. As the operator places his pen (e.g. 210) on thescreen and pushes. Cameras 170 image pick up location can be digitizedby high speed circuit at the frame rate of the TV camera which can forbest operation run as fast or faster than the primary projection.

If further information is desired such as the force and therefore thedepth which the screen deflects can be determined (and if desired thedirection) and this data fed as well to create either a shadingrendition of the TV projection or some other suitable modification.

Illustrated in FIG. 3 is the type of optical D-SIGHT image seen whenoff-axis illumination is used, as is illustrated in FIG. 2. In this casethe light and dark regions of the image of a local indentation reflectthe curvature of the surface, with a zero crossing indicating thecentroid location in the direction scanned. In the case where the forceF is not normal to the surface, the surface is indented in a directionat a (non normal) vector 249 to the surface, 250.

One can, with both on and off axis illumination, measure the distortion(elongation) in shape in the D-SIGHT image of the local surfacedistortion, as shown in FIG. 3B, to determine the force vectordirection. For utmost accuracy, means may be employed to calibrate (andstore in calibration tables, to be applied to the instant distortionsdetermined) said distortion as a function of vector direction, if themovement is non-linear for a given screen material.

As shown in FIG. 3 c even a hand print can be used to enter data, witheach finger, thumb and palm registered by the camera, and classified bythe computer system in proportion to their deflection and force. Thiscan be useful for the handicapped, and for security systems. It also isuse full as each finger can register independently and thus a keyboardor other touch guide printed or indicated on the screen can be activatedby each finger even simultaneously.

It should be noted that the calibration system mentioned above isparticularly applicable if one wishes to sense the force vector. Theoff-axis D-SIGHT version in particular is capable of showing the actualshape of the distorted area from which one can infer a direction offorce. This is particularly true if one assumes that the object isreasonably well known. For example, one might have a particularcalibration set up for a pencil or pen point whereas another calibrationmight be used for fingers. indeed, one might even precalibrate a certainperson's finger or handprint for maximum accuracy. Such a hand print isshown in FIG. 3 c which shows the XY outline and Z force darkening wherethe hand signature appears and the 3-D shape that can be printed outtherefrom. Its noted that such a “Print” can also be used to identifyand or determine the location of objects placed on a pad according tothe invention, as for robotic pickup.

As described above, a dark centroid indication can be detected relativeto a uniform background indicating little surrounding distortion. Ifthere is however some hysteresis, that is, that the surface does notimmediately go back to its original location but stays slightlydeflected, then one can actually sense the distortion not relative to azero-base but relative to what it was the previous time simply bysubtracting the two images (or answers) and then normalizing the twoinputs. This means that this has a very desirous capability of makingthe system impervious to let us say wear on the screen manifestingitself as permanent or semi permanent distortion.

Another salient feature of distortion detection employingretroreflective systems, e.g. D-SIGHT™, is that the readout isrelatively immune to the overall shape of the screen. This means thatinstead of being flat as the screen is shown here, it could even becurved in any shape whatsoever within reason. This allows convex screensto be used, for example in a game where the human interacting with it is“surrounded” by the screen, and he can hit out at objects coming fromdifferent directions toward him say. Convex screens in the shape ofhuman torsos can be provided in medical simulations to allow a surgeontrainee to “Cut” the screen with an indenting “Knife” simulating anoperation, for example.

Touch Screen Material

A front surface for touch screen embodiments of the invention which canmaximize deformation under load, and therefore sensitivity thereto, isstretched rubber as used in other applications of projection TV'salready. Stretched rubber (e.g. latex) has the ability to be extremelydeformable on a local basis thereby improving the resolution of thesystem of distortion in general. since even if the camera distortion canpick up images to within a part in 10,000 in both X and Y, the elasticproperties of the membrane or other structure that is used for the faceplate so to speak, is perhaps the limiting resolution factor, since thestiffer this member is, the more it tends to delocalize the effect, thatis broaden it out, over a larger area thereby making it more difficultto distinguish a precise point.

Obviously rubber is an extreme case of a membrane which could literallydeform around a point of a pencil for example. Not always is thisdesirable either, as stiffness is sacrificed. Because of this, plastic,glass, and the like are preferable for most touch screen applications ofthe invention, where rear projection is used. In front projection, anymaterial can be used, even painted steel.

Note that the screen material may also be chosen for the feel itprovides to the human interacting with it via touch. For example, insimulating the petting of an animal in a children's petting zoo game,the screen should be somewhat deformable to give as real as possibleflesh like feel to the child as he strokes the animal image on projectedon the screen. For simulation purposes, the animal can give outdifferent sounds, and make movements using video called from memory (orcomputer generated if animation technology is used) in response to theinputs made. Even voice input can be combined with touch.

Note too that one can have interchangeable screens, where differenttouch or other characteristics of the screen are chosen to suit theapplication desired. Further characteristics can be screens withpreprinted characters or colors, special overlays on portions of thescreen, active touch feedback, and the like.

FIG. 4

FIG. 4 illustrates a block diagram of a touch screen embodiment of theinvention. Steps involved in a particular case using a D-SIGHT basedsurface distortion measurement are shown on the right hand side of thefigure. Other grid based or photoelastic systems would functionsimilarly, in so far as their input to the computer 185. (and anyspecialized processing circuitry or software, 184).

FIG. 5

It is an advantage of the invention that the screen material can be ofany type as long as it sufficiently deflects (or other wise registers anappropriate optical signal) and is capable of withstanding the force ofa projectile or other object which touches the screen. As pointed outabove, the device is usable with or without the rear projection or otherdisplay on its face. For example, simply as a digitizer or as a deviceused for firing ranges where the front screen would be made out ofKEVLAR and the system simply used to find where the bullets land andoptionally at what force which can be imputed to their terminalvelocity, etc. This is highly useful for firing ranges to allow directinput, statistical monitoring, etc. back to the firing point (Inessence, a permanent target so to speak). The use of simulation however,with such a device, makes it even more exciting where one can actuallysee combat scenes on the screen and fire at them. In this case, thelarger the screen the better to make this scene more realistic.

The interactive video ability is electrifying. One can see a 3-D imageon the screen, and throw, fire or otherwise direct a projectile at acertain point on it and then see immediately through the use of videodisks or the like the result of the action with an image called up frommemory to correspond to the data read out by the camera 160 relative tothe impact. This could also not just be from projectiles but also fromactually hitting it with your fist.

FIG. 5 illustrates a ball throwing application of the invention whereina person 500 throws a ball 501 at screen 101, on which for example apicture of a second baseman is shown. If the ball is detected to hit atthe proper location and velocity, the second baseman is shown to catchthe ball on the interactive video displayed.

If however, the ball was thrown improperly, the second baseman video canshow him running to a wrong location on the field, or missing the ballentirely. In this manner the person 500 can “play” baseball. Similarly,he can hit a ball with a bat at the screen, or whatever. The videostorage 520 is used by computer 185 to select and display the propervideo sequences.

Further illustrated is another embodiment of the invention employingtarget datums as a man machine interface which can be used independentlyor in combination with the surface distortion as shown above.

As shown, the person is tracked in space with targets on his hands 530and hat 531 from overhead using cameras 550 and stereo photogrammetry.As shown in the inset, typically there are multiple target sets, on allobjects, to allow multiple degrees of freedom (even all six, such as x,y, z, roll, pitch, and yaw,) of position and motion to be detected, andto allow all fingers, wrist movements, other joint movements to bediscerned separately as desired.

Let us consider the operation of the system. The best results areobtained when the human operator or other data entry object wears on hisperson, at the areas which need to be identified, retro reflectivetarget datums, which can be illuminated from various camera positionsand are clearly visible and distinct. This allows the a low cost targetrecognition processor 570 to be used. Image processing occurs at realtime camera rates e.g. 30-60× a second and creates little ambiguity asto where target points are.

In a case of a large number of targets in the field of any one camera,there needs to be a coding provided such as through target shape,arrangement, or color codes (where color cameras are used. The use ofsuch passive retroreflective targets are considered less intrusive thanactive LED type targets. New, is the ability of the invention to takethis data into the computer to perform a task, and the use incombination with the surface distortion embodiment invention to providea complete solution for creation of a sensing environment of the person.

For example, in ball throwing, the position of hands, and other parts ofthe body are also important in determining its trajectory, spin, etc,and these can be recognized by activity computer 580 and computed tofeed data to the control computer 185.

There is a major advantage of the above invention for the physicallydisabled. The Intent is to provide data inputs to the computer so thatthe disabled can indicate to the computer where he would like a type ofdata entry to be made without the necessity of doing conventional passfor such efforts such as the touch screen, keyboard or mouse. It isnoted that the target tracking can be used in combination with thesurface distortion imaging described above to allow other extremities tobe utilized to make such indications as well. For example, the person'sfeet, it could be touching a “pad” which was imaged from the bottom soas to detect the positions of the heel, toes, whatever or other featuresand the various forces if desired that were exerted. This could be evendone lying down, where the persons whole body was on the device. Both ofthese inventions, in fact, are suitable for patients in bed.

It is noted however, that this invention can be used for other purposesas well; such as the ability to enter dance steps wherein the feet areable to move on the pad as shown and the hands, and head movements aretracked overhead. This allows one to do a dance, and enter the data intothe computer for the dance. This also holds for sporting events, tennis,etc.

In addition, it is contemplated that under certain conditions it maybepossible to utilize even naturally occurring features of the person;such as the tips of the fingers, the centroid of the head location, etc.to act as targets. For example Matrox “Image 1200” image processor forthe IBM PC can locate a finger tip on a contrasting background within afew seconds. Peoples features and clothes can be “taught” to the systemto increase the ability to locate the feature in question rapidly inspace. Templates or coding mechanisms are created to match the featurein question.

The stereo cameras can be located as well right at the screen, lookingoutward at a game player, for example. The cameras can be built rightinto a rear projection TV set in this way, and serve double duty asinputs to video TV transmission for teleconferencing or other purposes.

Objects for data entry can also be artifacts that humans use in gamingor other activity. For example, a steering wheel of a simulated car canbe targeted, as can the gear shift lever, etc. Changing the game to aplane, boat, golf club, bat, paddle, racquet or what ever, only meanschanging software, as determination is via the computer vision system,with no need for wires etc to the object artifact. Other non contact, orcontact detection systems can also be used where appropriate.

Other sensors which can also be used to determine human or objectposition include radar sensor, or ultrasound with a transmitter, forexample located on the person, or with a transmit and receive functionprovided on the TV set, allowing passive human interaction. Even aphased array radar, that can tell the location of a number of theobjects in front of it can be used. Such location is important in manygames, as one would like to control the video display as to the positionof the player, and what he's doing. This is not just limited to overalllocation or a head tracker, but can be expanded to encompass thegestures and movements of the player.

FIG. 6

Consider the case of FIG. 6 which shows the dancers whose foot patternson floor plate 610 are dynamically monitored from the distortion of therear of the floor, including the forces and the vectors of the forceswhich indicate their particular process. (As well their hand and headmovements can be monitored from above using cameras, not shown, as inFIG. 5).

For illustration, in this example a grid projector 608 is utilized toproject a grid on the back surface 611, which is imaged by TV camera 609which detects via computer not shown local distortions in surface 610caused by the dancers loads. Each foot location (4 total) is monitoredindependently, by detecting the local distortion beneath it, bycomparing the grid in a rest state, to the one under load. As the overall grid shape can change, the change in the grid image can be timedeterminant. For example the average of the last 5 seconds of gridlocations, can be compared at a local position (under a foot, say) tothe instant one obtained in 33 msec. for example.

Triangulated Grid image 650 illustrates the case of shallow curvature ofthe surface 611 with no local distortion, whereas grid image 660 showsthe effect of local distortion of two dancers.

It should be noted the touch pad can be used to identify ordifferentiate the people, via there foot patterns of indentation of thepad, or there signature of movement on the pad for example. Suchidentification can be instead of or in addition too any differentiationprovided by viewing the people or coded targets thereon directly. Alsoco-ordination between foot movements, a targeted object and a projectileor other contact with a touch screen if used can be combined, so we knowhow an object was kicked, or who kicked it, etc. As another example, Theposition of the feet and the hands at the time the foot detection, orthe screen detection of impact is made—all of these things can correlatetogether to make the correct identification or determination. Note thata projectile, such as a soccer ball can be tracked by the camera system.

The Importance of Stiffness

One key feature of the invention is that the optical distortionmeasuring device can have high resolution, allowing the surface memberto be stiff while still providing an indication.

One of the key reasons why the D-SIGHT invention of ref 1 is so valuablefor use in this invention is that it provides a very large area coveragewith the possibility of detection of minute deflections. This is ofgreat importance because of the need to have the surface member as stiffas possible in general to oppose the pressure of the touch and to createa uniform panel which can be used both for as a screen for television oras just simply a facade on some other instrumentation such as adashboard, a writing tablet or the like.

For example, sheet steel 0.035″ thick when pushed on with fingerpressure will create a discernable indication on a 2 meter square panelimaged with D-SIGHT. Indeed one can visually on the TV screen traceone's finger when pushed on from the bottom, by looking at D-SIGHT imageof the top of the steel.

A key problem however is to keep the total deflection down; for example,between the points suspended. For this reason it may be necessary todivide the system up into cells as shown in the inset, with thestrengtheners at various cross positions which unfortunately cannot bemeasured at that point.

The D-SIGHT represents to my knowledge the most capable in this of allthe technologies for measurement of surface distortion.

FIG. 7

FIG. 7 illustrates an embodiment of the invention used for automotivedashboard or other touchpad keyboard type computer entry use, furtherillustrating multiple inputs and segmented pads.

As shown the pad 700 on dashboard (not shown), is located at aconvenient position, and is used to input commands to the cars system,such as heat, light, etc. The particular thing of interest is that theindex finger or thumb such as 710 may be used to press down to establishfunction, and the next finger over 712 used to act as a slider fordegree of function desired. One can also give commands via sequentialpulses, and also by the degree of pressing in, or the force vector.

Clearly more than one finger can be operative at a time. Two such forceinputs are shown, 720, and 722, corresponding to action of fingers 710and 712.

Of interest is that, where desired, an unsegmented pad can be used. Forexample, one doesn't need to care where the first input is as its homeposition is noted by a strong z force, (say by finger 712) and thecloseness of the remaining forces (finger(s)) is the degree of functiondesired (say fan speed).

The pad can also accept a hand print, as a means of theft prevention, ataught signature can be recognized for starting the car.

The membrane used can have certain characteristics as well. It mighthave certain states such as undeflected, partial, and full deflectedwhere it would snap like in a digital way. Note that you couldphysically vibrate the membrane with a Piezo crystal such as 705 undercontrol of action generator 730 to cause a feedback signal to the user.In other words, if you were driving a car and you push in on themembrane when you reach a first point it would vibrate. When you reachthe second point it could vibrate at a different frequency, orintensity, or pulse sequence, say.

The screen material may be composed of something which itself canvibrate such as piezo excitable or what have you. This then provides afeedback signal to the person touching the screen. Conversely, one canactually have at a position, a physical force element such as an air jet740 or what have you, that actually feedbacks data to the touchedpoint(s) in its area of operation. Feed back can be also be via alocally variable deflection with force (variable modulus of elasticity)too, based on some input that would cause the screen elements to stiffenor relax. Air pressure variation in cells of a transparent screen, orpiezo elements etched in transparent silicon screens are possiblemethods which could be used.

It isn't just multiple points that can be detected. A complete “area”signature can also be detected. For example, a hand print can bedetermined from the deflection of the screen. Indeed, the device iscapable of being used in this mode as a robot hand. One, forgetting thetouch screen capability, where the imprint or impression left of thehand or any other object onto the screen, can be detected as such fromthe shape change of the screen.

Besides the use as in robot hands of detecting the part that might bepicked up, it can also be used in the case here for example, inautomobile to help one to identify from a written signature or a handprint or something, whether a qualified driver is present or not. Thefact that it is not just 2-D but 3-D is a major improvement in thisscore. Other applications would be security systems for entry intobuildings, even using the dynamic 3-D footprint of the personapproaching the door if desired.

FIG. 8

FIG. 8 illustrates a further embodiment of the invention, illustratingthe use of another method of optical image based surface deformationdetection, coupled with a detection of electro, magnetic impulses orforce fields.

As shown, a screen member 801 according to the invention such as 101 inFIG. 2, but in this case simply acting as a transducing medium and nontransparent, is laid out in the form of a membrane with a grid of lines810 on its surface, and illuminated by light 817.

Membrane deflection due to a time changing (or static) electromagneticfield F, produces a change in the grid pattern of light when viewed froma camera system 816 through a moire grid, 820. By known moire principlesthe distortion of the surface can be identified, and if desired, thedegree of distortion calculated thereby. Clearly other time varianteffects such as pressure waves from a loudspeaker, thermal effects andother phenomena can also be so determined.

Alternatively, the grid need not be located on the actual membrane butcan be projected onto it in as in FIG. 6.

The use of TV based optical imaging to determine distortions over alarge area at high speeds, is an important feature which helps theinvention. While not as light efficient nor as useful as the FIG. 2device, this nonetheless can provide the images. It is noted that acombination can be utilized wherein the grid pattern is on the screenand is viewed in this manner, also in conjunction perhaps with a moiregrating or not.

FIG. 9

FIG. 9A illustrates a variant to the invention along the lines of FIG.2, where the index of refraction of the material of screen 900, and itsvariation due to touch, hit, or other impact, F, is determined, whenilluminated by light form source 905. In this case the camera 910 or, asshown in the figure, the retroreflective D-SIGHT screen 920 can beoutside of the housing 925, if desired. While not generally desirable,there are certain types of simulations, etc. where this might bedesirable.

FIG. 9 b illustrates an interesting projection TV arrangement whereinthe beads 949 on the screen 950 act as retroreflectors for light used tomeasure the photoelastic stress in the screen material, while acting asdiffusers for projected light from the TV guns and associated optics960. Here, surface touch is converted to stress as opposed to adeflection. This stress is monitored over an area.

A touch pad screen according to the invention is thus contacted in amanner which creates a stress in the photoelastic member attached to asurface, or within the material having a surface. In a manner somewhatsimilar to the D-SIGHT invention, light penetrates through thephotoelastic material member, strikes a surface behind it and isre-reflected back through the member. In this case it is not thedistortion of the re-reflecting surface that is measured but the stressthat has been placed into the photoelastic material. By using crosspolarizers and known photoelastic techniques dependent on thedifferential index of refraction change with stress of polarized light,the stresses in the material can be monitored by TV camera 970 and thisinformation converted to knowledge of both location of the stress,caused by the impact or touch, and its degree. This in a way is a bettermeasurement of touch input than is deflection and allows the padcontaining the screen to be very stiff.

There are problems with this system insofar as projecting light, sincethe rear surface (on the other side of the material whose refractiveindex changes) must be reflective and as a touch screen for projectionTV for example it's difficult, although such transmission would bepossible if the rear reflecting surface was not totally reflecting withthe projection unit as shown.

Projection TV, it should be noted, is not the only way of doing this.One could have LCD type surfaces on any of these devices which wouldcreate a TV image on the touch screen of the invention.

Another embodiment of the invention uses a transmissive version. In thiscase the screen is located at an angle, and indeed has on it the LCDcapability described. The light is projected through the LCD screen.

Summary of Applications of the Invention

Principal Application Areas of the Disclosed Invention Envisioned at theTime of this Writing are as Follows:

1. Aids to the disabled, where the unique force vector and multipointand signature response characteristics of the invention can be used toadvantage, to provide enough information so that an intelligent decisionto what an input was supposed to be can be made.

2. Data entry over larger surface areas such as desk top CAD systems(which may or may not be combined with a touch screen), projection TVscreens in the home or in video arcades and the like.

3. Interactive video games and simulations in general, where a touch,hit, etc., input is sensed with the invention.

4. Large simulations or displays (as in war rooms).

5. Practice such as, firing ranges and sporting events such as baseballpractice, where a projectile “hit” input is sensed.

6. “Feeling” Touch screen or touch pad data entry, also at multiplepoints simultaneously where image objects can be rotated, moved, etc.

7. Special transducers e.g. for transient forces, also at multipleessentially simultaneous locations.

8. Automobile and aircraft cockpit or other data entry devices both intouch screen form and simply as a data entry device for example with ausable heads up display.

9. Non conventional data entry situations, as in feet on the floor, andsignature analysis thereof, or hands on pad, for security and otherpurposes.

10. Medical analysis, for example of bone and muscular disorders asmanifested as foot signatures on a touch pad of the invention.

Partial Re-Summation of Advantages vis. a vis. other known Touch Screensand Pads:

1. The invention can provide a 3, 4, and 5 dimensional touch screen orgraphics tablet. In other words, the x,y location of the touch, theforce or depth of the touch, and the vector direction of the touch (2angles).

2. The technology is simultaneous multi-point. In other words, not justone finger can touch the pad or screen at once, all fingers can touch.In fact, not only can the fingers touch, wrists, elbows etc can also beregistered (leading also to aids for the handicapped). Indeed 20, 30,40, 50, 100, or even 1,000 contacts at once on a given screen or pad canbe registered.

3. It is very well suited for very large screens or pads. This meansthat it can be used for wall sized simulations of hockey games, soccer,basketball, racquetball, military firing ranges, cockpits, and any otherdesired activity. Security systems, weighing and other transductionactivities are also possible.

4. The screen in which one forms a touch screen can be virtuallyanything, because the screen itself is not the sensing medium, althoughits deformation is sensed. This means that all sorts of materials can beused as touch pads or screens, including and not limited to glass,plastic, armor plate, steel, KVLAR, etc.

5. The invention provides the only known ability to easily incorporatetouch screen, let alone a 3-D touch screen capability, into a homeprojection TV. This has a wide ranging potential application for use inhome shopping, and other remote data entry devices for the home, inaddition to gaming and amusement. Any time you see something on thescreen you can throw something at it or touch it—without the need forany special pens, wands, etc.

The ability to have such an interactive projection TV of let us say the40″ screen size and larger furthermore opens up a wide market for videoarcade games, even ones which could be played in the home. The touchscreen capability allows one to not only touch the screen with one'sfinger but given a suitably strength of screen, one can hit it with anypart of the body, a projectile such as fired from a toy pistol of eventhrow baseballs at the screen, whatever.

When we add to that capability of having the video display not only showa video tape which could be made by the user himself, but also utilizingthe latest 3-D display technologies such as that released recently byToshiba, etc. to have a three dimensional TV with alternating images.One can actually have not only a 3-D touch and interaction capabilitybut also a 3-D display capability. All of this on a capable home systemwhich costs typically no more than $4000 in quantity.

When one considers the military and police simulators of the same ilkbut perhaps with larger screens projecting let us say military or policecombat scenes onto a screen perhaps in 3-D and allowing the trainee toactually fire at the screen with pistol or what have you. It would onlybe necessary to have frangible or hollow rubber bullets or somethingthat would deflect the screen but not damage it in order to make such asimulation which would be as close to “real combat” as could possibly beimagined in the laboratory.

Similarly, displays or even just entry devices simulating the strikezone of a batter could be used for pitching practice in baseball. Videoplays could also be made from a quarterback's eye view for football andyou could throw the football at the screen registering at the screen thevelocity and effect which would allow one to have a computer determinewhether or not the receiver would have caught the ball. The same holdstrue with soccer, hockey, etc. dodging a goalie to kick a ball in, say.

As with all of these examples, the new generation of interactive CDdisplays and other optical memories would allow one to call up differentimage sequences depending on the 3-D sensed information from the touchscreen. In other words if the quarterback threw the ball in such a waythat it would be caught, one would simply have a video display of theball being caught. However if the throw was off, let's say to the rightor to the left, you could have a video display of that.

Virtual Reality and Simulation using the Invention

To aid the interaction of the human with the computer in a way thatallows the human to experience what the computer can simulate, improvedmethods are needed by which data can be more rapidly entered intocomputers, indicative of human wants, such as rotation of objectsdisplayed on a screen, which have been designed, or otherwise createdfor animation etc. Some of these are often called virtual reality, andvarious means, such as position monitoring of head movements, “datagloves”, which include measuring finger positions and joints, etc. havebeen proposed.

The touch screen of the invention can also be so used. It is simple andunobtrusive to the user, and monitoring 3°-5° of freedom of position andforce of finger touches to an opaque or transparent screen, capable ofdisplaying the TV image, allows imputing data to the computer controlsystem to allow the image, or other data displayed to be modified inresult of the human inputs.

FIG. 10

FIG. 10 illustrates a gaming simulator according to the invention usablein sports bars and home family rooms, for example. An overheadprojection TV 1001, projects the video images desired, for example,still, video, or a combination thereof onto the screen 1002, which canbe, per the above disclosure, either flat or curved.

The projection can be using known principles, either provided in aconventional manner, or in perceived “3-D” form, where special glassesor other artifices are utilized by the players, which may be one ormore. In the three dimensional case, the added advantage, shown in FIG.10, is that the goal or other target aimed at by the player can forexample, be located apparently well behind the screens physicallocation. The single player case is described for clarity, but issimilar to a multiple player case.

The goal of this simulation embodiment is to provide as close to reallife gaming experience as possible within the cost constraints ofaffordability with respect to the actual projection TV system itself,which typically today runs on the order of $5,000-$9,000. In theparticular examples shown, a Sony projection TV system capable ofcovering a 120″ screen is provided. Larger more life-size units can alsobe used, where required for life-size gaming for example. New digitalprojectors from TI and others may make 20-30 ft screens possible in fullcolor.

The goal of the game in the soccer mode, for example, is to kick asoccer ball at the screen, wherein a video depiction of actions of aworld famous goalie are portrayed through the video system. A sportsgaming module is provided, concerning the TV projector 1001, screen1002, screen deflection measuring subsystem 1005 (built along any of themethods of the invention), video system to create material to beprojected, 1006 (either from prerecorded matter, computer generatedvirtual imagery or whatever). This video system can include data takenstraight from laser discs with reactive imagery called up directly fromRAM memory in response to the sensed actions of the player taken (fromscreen deflection, overhead cameras, ultrasound, radar or othersensors).

For example, a typical soccer game is portrayed on a screen, as viewedby a player “forward” 1044 approaching the goalie 1045 displayed on thescreen. The video is chosen from data taken ideally as to where theforward, in this case the game player is. This data can be taken fromstereo cameras such as 1050 and 1051, or other devices as shown inprevious figures above. As the player approaches the point where hewishes to kick the ball 1053 to score a goal, the goalie's movements areideally called up from video memory to simulate what a goalie would doto looking in the direction from which the kick is to come.

In this case, the sensing system has determined the location of theperson such as 1044 about to make the kick (the sensing system beingfrom either TV cameras overhead coming outward from the screen, or usingthe invention, or other means to detect the location of the person onthe floor). The computer controlling the video display, 1055, thenorients the video toward the person, such that the goalie, for example,is looking more or less in his direction.

When the player makes the kick on a real ball, in the case of this lowcost simulation system, we really don't know where the ball went (unlesswe had expensive ball tracking systems) until it hits the screen. Whenit hits the screen, we then can calculate from above, the location ofthe ball hit on the screen, and either knowing the location of theperson who kicked it call up video from the projector showing where itwould have gone. Conversely, using the invention to determine the shapeor distortion of the screen, the trajectory of the ball, can becalculated as noted above.

At this point the system computer 1030 then calls from video memoryimmediately such memory being in RAM storage, such that it can beaccessed instantly, the requisite shots showing the ball going inwhatever direction it did, and showing, if desired, the goalie trying tostop it.

That effort completes the simulation at that point. A score for how goodthe kick was, how close to the goal it was, where it was within thegoal, or the actual soccer score itself, as in 1 or 0 (depending onwhether it went in or not), is registered, (and if desired, displayed onthe screen) and the game continues with either other players, orwhatever.

Because of the multi point aspect of this invention, and the ability totrack multiple players in the field approaching the goal (or othertarget). One can actually have multi-person games, where the ball isactually passed between one and the other, and the actions still trackedand the game played. A floor based sensor system of the invention cantrack the location of players feet and the ball too as it impacts thefloor. TV cameras or other means as described herein, can track theplayers as desired.

What has just been described in terms of a soccer game is clear with allgames having a goal, such as lacrosse, hockey, rugby, and to a degreeAmerican football, in which case the goal is typically a goal line,except for the extra point kicks.

In order to execute the invention with video responsive to position,there is a means to detect the rough location of the person, and a meansto detect the location of the ball in at least x, y, and z when it hitsthe screen. From these two pieces of data, not only can the actions fromthe video in the computer means be called up, but also the calculationas to the direction and distance that the ball might go.

Further illustrated in this figure is the issue of dynamic targetdetection. This goes beyond the description shown in FIG. 5 above. Inorder for the gaming simulators of the projectile type to work, such asthose described in this figure, and in FIGS. 5 & 6 above, it isnecessary to determine dynamically the location of a projectile impact,as well as, if desired, its z axis force/deflection, and potentially itstrajectory, as well, from the shape of the disturbance on the screen. Toprovide this function, the camera system, or other optical, ornon-contacting system observing the back of the screen has to be able torecord the event in real time.

The first method of detecting a dynamic distortion is to simply take theframe of the camera, typically operating at a frame rate of 30 or 50hertz, and analyze that frame each time to determine if something hashappened. The frame then will handle the D-SIGHT image, or deflectedgrid image, or a triangulated grid image, or whatever type of full fieldimage from the screen is desired, and the determination is made. This iseconomic, as camera systems operating these ranges are standard andbelow cost. The question is will it work, where the dynamic nature ofthe event?

There are two answers to this. First if the event is of a slow enoughduration to where appreciable amounts of the event occur over the periodof the frame integration, then the answer is yes. The only trouble beingthat a single frame then may be taken one more time, cutting the event,so to speak, in half. If this is a problem a specialized frame camerathat records on an initiation of an event can be used. The eventinitiation can be determined by accelerometers, used to measure aseismic event on the screen, and therefore initiate the frame recording,or other optical means, as will be described, can also be used toregister the event.

But if the event is very short, typically occupying only a fewmilliseconds, for example of actual indentation, then within a 33 or 25millisecond frame, this is a small amount, and might go undetected.However, one of the advantages of the D-SIGHT approach is that the frameis integrated over the period, and thus a significant event that occursanywhere within the period will be registered. This is also true of manyother types of grid distortions, etc. The only thing is that the signalto noise may be less than it otherwise would have been, although thisdepends on the magnitude, as well, of the event.

If this is not sufficient for dynamic detection of an event, eitherfaster cameras and processors can be used to search for the screendistortion, or a trip wire such as a photo switch can be used toinitiate the scan. For example, a light curtain in this case comprisingexpanded field light source and detector 1070 and extensiveretroreflector 1071 (extending out of plane of drawing) can be used toregister to computer 1030 that the ball or other projectile has passedthrough. Since it is a known distance “d’ from the screen of theinvention, the approximate time to impact can be determined, an theappropriate camera readout commands be given. In addition, if the lightcurtain has the possibility to register where the projectile wentthrough its grid, this data, and the screen impact data in x and y canbe used to calculate the trajectory of the incoming projectile.

For example, consider a dynamic distortion, in this case of the D-SIGHTimage used in a preferred embodiment to determine distortion of the rearof screen 1002 of FIG. 10, which illustrates the effect of a fewmillisecond indentation of a hockey puck on the front of the screen. Ifthe camera frame rate is sufficient, the distortion can be detected, andthe effect is integrated by the camera over the frame integration time.For example, if the effect is determined to be present in multipleframes, the one with the blackest or most area affected can be used toregister the event.

Alternatively, and where desired, an accelerometer such as 1090 canregister that the event has occurred, and this data can be fed tocontrol computer 1030 which can if desired, strobe the camera used tocapture the D-SIGHT image to freeze the frame integration after theevent has occurred. This then can effectively shut out all other videonoise from normal image events on the screen. However, this isn't reallynecessary where for example image subtraction (instant image subtractedfrom stored normal or quiescent image) is used, since in that case theevent only creates a non-zero answer when it occurs.

In an optional manifestation, the D-SIGHT principle is also utilized,but with a separate channel for the integration of at least a portion ofthe surface D-SIGHT image onto a position sensing or other analogdetector. This analog detector is set up in an AC coupled mode to beresponsive to change in the image. When such change is detected, ittriggers a flashed light or strobe of the camera shutter, which existslong enough to capture the maximum deflection or other desired conditionof the screen.

With D-SIGHT, the change in the image can generally come from theredistribution of light within the image due to the occurrence. Thedetectors are optimally ones that have an ability to discernredistribution. However, I have found that in some cases change existsdue to light exiting the system and other causes for at leastsignificant disturbances, and this change, a drop in voltagecorresponding to light not returning to the detector, can be determinedwith a simple photo cell.

While an optical detector as above can be used for a trigger, so canacoustic detectors. In this case, one simply listens for a sound, or avibration, via an accelerometer, and strobes the camera.

In another potential embodiment, one can free run the camera, but onlystrobe in the last frame, or last ‘n’ frames into memory, once theacoustic signal is detected. By storing the last ‘n’ frames, one cansort through these frames later, and find the best image for use inscreen distortion analysis (typically that with the stronger signal). Inaddition, the NTSC standard 30 frames per second are possibly too slowfor certain types of activity in an unstrobed mode, and faster camerascan be utilized.

Another alternative is to use an auxiliary second camera having lessresolution, but free running at high frame rate which is interrogated,let us say at 500 frames a second, to process the data, and determine ifone or more pixels are different from the norm, indicating an impact.When that pixel is determined, the main camera may be strobed, tocapture the impact at the resolution desired.

While optical readout of the screen for such target applications isdesirable, it is alternatively possible in the invention to use acousticpick ups for x, y, and to a degree z, (indentation) measurements. Uponimpact of the projectile, consideration of the time of arrival ofsignals at each, is utilized to determine the location of impact. Themagnitude of the signal sensed, is indicative of Z force of impact.

In a preferred mode of operation of the invention, at low cost today,prerecorded still images created by “Photo CD” or digital cameras areloaded in memory, and called up as a result of the location of the hit,or a touch, including the audio needed. Real time video can also becalled up.

Much of the same description of this simulation relative to sports canbe also done with firing ranges, where various ‘bad guys’ can be on thescreen, and one can shoot at them. In this case, one or more players canbe shooting at one, or more ‘bad guys’ on the screen, since theindividual hits can be registered even simultaneously with theinvention. It is also noted that the action of the bad guys to eitherbeing hit, or missed can be called up from memory.

A major difference between this firing range and those using ‘mass-less’laser simulators is that you can use a police officer's (for example)own issued arm, in the mode it is intended to be used—a major trainingpoint. Frangible rounds and downward slanted screens can be used toprevent or deflect ricochets. Even rounds with different impact shapesor amounts can be used to allow identification of one participant vs.another from screen deflection, allowing multi-person firing simulationsagainst opponents, situations or whatever.

A difference between most firing type applications and those of a soccergame is that in the case of firing, whether it's a gun, a bow and arrow,or whatever, is one can keep firing, and the game can continue, whereasin a sports context, once the ball is kicked that's it for thatparticular round (or hockey puck shot, or whatever).

In further considering the application of the invention to firing rangesfor the use in military and police simulations, the location (andoptimally force and trajectory) of the impact is detected, and a scoreis provided, relative to the location of and optionally severity of theimpact on the image represented on the screen. Images can be presentedof different scenes, and they can be presented in 3-D, where the screenis not at the point of desired impact.

Because of the ability to sense multiple points, even use of machineguns, and other very rapid firing systems can be used, since all of thehits can be registered, even if the frame rate of the camera is slowerthan the machine gun. This also is true for guns, such as shot guns thatfire multiple pellets, or projectiles at once. It is noted that thissystem can be used in real time, as well, to align sights with guns,where the sights are gradually brought into position with the actualimpact points of the bullets. This is, of course, and added advantage ofthe system for use in production of weapon systems.

In FIG. 10 example, it was chosen to use an Elmo model EM-102BWminiature solid state TV camera, positioned so as to be expanded via amirror to cover the majority of the screen. Reflection onto theretroreflecting material on the side of the TV wall and back to thecamera after bouncing off the rear of the screen. Typically the screenof a rear projection TV is a fresnel lens, which has an additional frontscreen in front of it, with striations to spread the light laterally.This front screen may be made part of the fresnel lens, or removed. Onecan optionally leave the front screen in place, and touch the screen,and from that, touch the rear screen as well.

An LCD screen display can also be utilized, and its deflectiondetermined. An LCD projector device can be used to project light on ascreen of the invention, including those of a particular type, usingalternating polarizations for 3-D display, if special glasses areutilized.

For ease of programming using today's video technology, the inventioncan use a combination of video background material, plus stills to orderas a function of the input. A background scene might be video, but thenwhen it comes to the action part of the video, initiated when one throwssomething, let's say at the screen, the remaining parts, the onesresponding to the action, are stills. The goal here would be to make itsimple to actually produce these without having to call numerous variedvideo clips from computer memory. As technology advances, stills couldbe compressed video. Important is to have near instant response, todayprovided by loading images into ram memory.

Keyboards

Another application of the invention is to provide keyboards for datainput on the video screen (or even with out video on the equivalent of atouch pad). One can video display any form of keyboard on the screen,and the keys can be touched in and the touch response registered. Onecan arrange keys in any way desired, and other parts of the body, notjust fingers, can be used to register inputs. Indeed the keys can be ofany size or shape. This has advantages for the handicapped.

In addition one can tell keys because one know positions where they areon the projected video display or overlay or because of a special keyindent shape or other signature. One can also create on the video newform of mouse, where sliding the finger on the screen or pad of theinvention, causes a pointer to move on a display. One can also displayon the screen a letter, which one can finger touch on the image directlyThe rear projection simulator of the invention can also be used tocreate a gambling machine as well, wherein video games of chance areinteractively used to “Play a game”.

Handwriting Registration and Analysis

Indeed the invention is a unique data input system. For examplehandwriting can be registered on the screen and analyzed using suitablesignature analysis programs. The screen deflects in proportion to datawritten with objects, or fingers, or whatever, and the information isanalyzed.

Additional methods by which to determine the location, force, anddirection, if desired, of the contacting screen, or touch pad of theinvention are now disclosed.

In an embodiment shown herein, the characteristic of the screen isdetermined in its natural state where no input has been made. Thisnatural quiescent state representation is stored, and compared at afuture time to its instant state, with any differences noted in thedesired location, force, or direction of the touch, or other screendeforming activity.

Optical imaging of the screen using a grid projection technique,employing retroreflection is utilized. In this case, the image of thegrid, is made using the retroreflection principle where the light isprojected onto the rear surface of the projection screen, then to aretroreflective panel such as made of Scotchlight 7615, on which gridbars have been provided, then back to the surface, and back to thecamera. The image of the grid bars are provided, and stored. Instantimages henceforward, for example every frame, are then compared to thestored values for deviations. Indeed, the deviated image caused by thereflection from the part surface essentially creates a Moire effectbetween the stored image, and the instant image, which can beimmediately determine the distortion condition of the screen. This isdifferent than described above (FIG. 6) in that it is the grid that isimaged, not the screen, and thus it is the reflection from the screen,rather than any image variation from the grid on the screen that ismeasured by the camera system.

It should be noted that an alternative version has the grid systemprojected from a point near the camera, as shown in dotted lines, allowsa smaller grid to be utilized with a simple retroreflective screen,rather than the gridded screen shown. In both cases, the grid can bevaried, either by mechanically switching the imaged grid, or byeclectically changing for example if it is an LCD generated type.

It is also possible to use the invention in this form to simply subtractthe original image from the instant image, since with no change thesubtraction is exactly the same, any instantaneous effects will causesome point of the image to change. This is true whether, or not theembodiment employing determination of a characteristic of deformation ofthe screen using a D-SIGHT image, such as 2 above are utilized in eitherthe on-axis, or off-axis mode, or whether the grid images here describedare utilized.

It is also possible to process the image to determine the location of atouch or impact, and simply subtract the processed answers, as opposedto the ‘raw’ screen image distortion data. This does not appear to haveany advantage however over the a royal subtraction, unless one needs todiscriminate against background noise that would otherwise still appearin the subtracted image.

It should be noted that the measurement of the deformation of the screencan vary. For example, in the versions which reflect off the screen,such as FIG. 2, it is basically the slope of the screen that is beingmeasured, particularly the instantaneous slope around the point, orpoints, of contact of the touching object, or objects. This screen slopemeasurement is essentially because of the fact that Snell's lawgoverning the reflection from surfaces is acting to ‘move’, and thusmodify, the effective points of the image of the grid on the screen, orin the D-SIGHT effect the actual light variation returning to thecamera.

However other methods of screen deformation measurement such as FIG. 6,may use triangulation, in which a zone of light, be it a spot, line, orgrid projected onto the surface of the screen itself, and then imagedonto the camera system in some manner, (whether it's with scanned laserspots, or all at once with grids, or whatever).

In this case it is not the slope that is being measured, but thedisplacement at the point of contact.

This is typically not as sensitive to screen deformation, but suchsensitivity in certain cases of pliable screens, and the like, may notbe desired.

Another interesting point about triangulation is that for the grid andD-SIGHT reflection type methods used for slope, desired at the rear faceof the screen being looked at is quite reflective. For types usingtriangulation, it is generally preferred that the rear face of thescreen is somewhat diffuse. Given the close tolerance TV projectionrequirements, either situation can be accommodated since there is noimpact on the TV image projection on either case.

The measurement of deflection slope or shape can be used as an indicatorof touch screen or pad position or other characteristics. A finger touchdistorts the screen.

FIG. 11

Another type of effect can be utilized to determine the location ofscreen distortion or deflection, wherein the direct reflected lightfield from the TV screen rear (or front) surface is viewed by a cameraor other electro-optical detection system. The reflected light from thesurface, which is ordinarily flat, or slightly curved in a typical TVsystem, becomes locally changed due to the effect of the touch, hit etcdesired to be detected and located. Unlike the somewhat similar D-SIGHTeffect, this has nothing to do with retroreflection, and uses but asingle pass on the surface.

As shown, camera 1100 looks at member surface 1110 illuminated by lightfrom light source 1115 which has been reflected from the back surface1120 of projection TV screen 1130. On surface 1110 a dark spot 1140occurs due to the indentation 1135 of screen 1130 by an impacting hockeypuck (not shown for clarity). This spot is caused by local surface slopechanges which direct light at that point away from where it normallywould have fallen on surface 1110. The camera output signal is comparedto a threshold value and if the level drops below the threshold, aindentation is determined to have occurred at the point in question inthe image field of the camera. Alternatively and desirably, thisthreshold can be compensated for normal variation in light field acrosssaid screen, and can if desired used the calibration technique of FIG.16. Indeed many other ways to detect such events such as describedherein or other wise can be used, such as differentiation of the camerasignal to determine points of rapid change indicative of a local hit.

While one can therefore simply use the camera to look at the reflectedlight from a surface of a TV screen or pad, as shown in FIG. 11, this isnot as light efficient as the use of the retroreflector, but is capableof monitoring the data desired.

With very weak signals of indentation or other screen deformation, theretroreflector techniques, or the moire grid comparison techniquesdiscussed are quite sensitive. It is possible to use an analog imageintensity or position detector (PSD) to see some of these effects. Inparticular, relative to noise, the analog detector, TV camera, or otherdetector, can be gated so that it only views the signal at the propertime; that is when the actual event occurs. In this case the onset ofsignal is detected independently and cued by other means, such asdescribed above.

Conversely with strong indentation signals, such as feeling, grabbingand other actions using more deformable screens (i.e. not stiff), onemust deal with significant local distortion magnitudes. The gridtriangulation, conventional triangulation and stereo approaches cansolve most problems of this type.

Note that we then are basically sensing the slope, the contour (which isoverall shape), or the actual deflection.

It is also noted that other effects for measuring the screen can beutilized. For example, particularly in a front projection case, wherethe screen is opaque, the grid can be placed, physically on the rear ofthe screen. In this case, Moire techniques can easily be used, where animage of a grid on the screen is compared to an image of a stored grid,or of the same grid, for example, taken at a time where a screen was notdisplaced. This deformation of the screen then creates an immediateMoire effect. Indeed the reference grid can be located right behind themain screen grid.

Similarly Schlieren techniques can also be used to determine the slopechanges in the surface, wherein fight is viewed a stop, and light thatescapes past a stop due to slope changes is detected. Theretroreflective technique however, shown in FIG. 2, is a method ofmaking such systems in the simplest and least costly way, since all thelight can be easily projected from a small lamp under the totality ofthe screen, and back again without complex optics, or expensive lights.It also tends to make it easier to operate on curved screens.

It is also noted that one can make the measurement by looking for thechange in screen shape, or alternatively, if only an indication isdesired, the fact that a shape change occurred. For example, by actuallyreading out the grid lines, and determining that one, or more are notstraight, and if so, where one can operate the invention. This can bedone either on a slope basis, or on a deflection basis. In either case,the ability to look at a large area, and find the point that made themaximum deflection, or slope change is quite different than thatutilized in other types of measurements of, let's say, diagrams, whereit is only the maximum point that is desired, as in pressure gages.

Note can measure deformation of the screen in an original undisturbedstate, store the image obtained (with or without processing it todetermine distortion therein), then subtract the instant test image (orprocessed version thereof)) or otherwise compare the original conditionwith instant condition Note to register a touch or impact, the screen isdeformed and a number of variables representative thereof can bedetermined, such as a specific shape, a curvature, more than one shapeor curvature, etc. A shape signature can be searched for. A secondderivative function of the surface can also be derived indicative of anindentation.

FIG. 12—Simulated Knobs and Levers, also with Screen Overlays

FIG. 12 illustrates a multiple simulator application type panel 1200,including instruments such as dial 1201, and programmable knob, switchand lever (or other actuation devices) features, where the actuationdevices are visually created using software on the screen, but actually“turned” by touching the deformable screen.

For example consider knob 1215, which exists as an image on the screen.By putting ones fingers on the image at the points one would touch theknob, and by indenting the slightly pliable screen a little ways andmaking a turning motion, one can get the feel of turning the knob—the TVimage of which, using the invention, follows the finger turning motionused. Since everything exists in software, one can immediately change toa different control function as desired.

Conceivably one could even use these touch screen panels not just forsimulators but for the real thing, i.e. a airplane or car dashboard orportion thereof, and change ones mind about where certain functionswere, just by reprogramming the video and touch screen of the invention.

FIG. 13

Where desired, an “overlay” can be placed over the screen, or somehowmade part of the screen, where the human operates the overlay function,such as a lever, and the overlay in turn touches the screen and deformsit to register the event, and magnitude thereof where desired. In otherwords, some sort of a lever contactor touches the screen.

For example consider FIG. 13 wherein overlay 1301 has been placed infront of screen 1305 and is viewed by user 1310. When the users fingers1320 and 1321 move the lever 1325 on the overlay, the overlay pin 1330indents (very slightly) the screen 1305 and causes the rear thereof toregister the position of the lever, as described in the invention.

Multi-use is thus also possible; that is with contacting overlays, orother things, plus being used in front projection, plus rear projection,plus video games, sports, etc. an made possible in one system.

For cockpit flight simulators, dashboard simulators etc., tactile feelwith programmability using the invention to achieve say a cockpitsimulator of a Boeing 737 and a Dehaviland Dash 8 at different times isa big advantage. A key issue is something that is multi-point so thatone of the control action, which could require two actions at once, likethe throttles can be accomplished, and something that is a multi-pointtype function, and gives the sense of a rotation, turning a knob forexample. Sliding, rotating, switch throwing are all examples offunctions of interest.

For tactile feel there are interesting possibilities inherent in thetouch screen of the invention. Clearly the projection touch screen canbe deformable, which the heavy normal CRT glass can not, unless you putan overlay on it.

One of the ideas is to have the material, somewhat deformable, forexample latex, or something stronger. This would allow one to sort ofget the feeling that one was twisting something (e.g. a knob), eventhough it was not really twisted much. One might also sense thought thedeformation in shape of the screen material, a characteristicproportional to the torque, or moment exerted.

For indenting something, as you would push the deformable material ofthe screen, you would get the feeling of resistance, and it's a littlehard to say how this would work, relative to a push lever, or toggleswitch, or something else. But it has a certain, at least, partial feelto it.

A touch screen overlay can also be transparent, but without the parallaxinherent in thick overlays, because the rear projection effect allowsone to project right on the front (i.e. the side facing the user) of theplastic overlay system.

The invention allows not just the sensing of a touch, but the sensing ofthe function of the overlay—including its deflection if desired. Anoverlay push switch, for example, has a feel of going in and out. Itdoes not necessarily have to have it printed on the overlay, but thenagain it could be. The important point is that the movable needles, andother instrument features simulated are desirably from the stored TVimages projected from computer memory. In this case therefore, theoverlay is simply a push button that can deflect. But it's alltransparent so that the light that's going to say what it is comesthrough from the back on the regular display. This means that in apinch, it can also be operated without the overlay. The overlay addsbasically the tactile feel.

To operate this embodiment, you would only have to have an x,y touchscreen with the z direction sensed by the invention from the overlayportion. An overlay lever, could for example as well, simply be pulledalong and used to make a linearly increasing D-SIGHT “dent”, as afunction of its position.

Note that the knob turned can also be used in this manner.Alternatively, it can make a different definable shape of indentationwhich can be recognized by the invention.

The invention can not just sense what the driver say of a simulated caris commanding, it can also record the driver's actions in thesimulation—just to what the drive did with his hands, etc.

Note that if the slider, or push button, or whatever was actuallytransparent, the projected optical TV beam would go through it, and hitthe front face of it. In which case, it would look just like the regularone. At the edges, there would be some funny stuff, but basically itwould seem that you could build out of transparent plastic the variousdevices that were desired for the tactile feel.

In all embodiments, the touched screen can not only to be made ofanything that works, so to speak, it also can be interchangeable. Thisis a major feature that is not shared with any other touch screentechnology, and applies to both touch screens of the transmissive andopaque type. Interchangeable screens might include ones that were hard(stiff) for writing on versus softer, such as latex, etc. for feelingtype games, etc. It might include screens that had touching responsecapability, such as “click’ type details for typewriters, or evenelectronically actuated Piezoelectric bimorph portions of their surfacefor selective feedback to the response of people using them. Finally,other interchanged screens could also include overlays as part of thescreen or that could be attached thereto for different functions, suchas sliders, rotators, rotating knobs, etc.

Another embodiment can have a touch screen overlay, but without theparallax inherent in thick overlays, because the rear projection effectallows one to project right on to the plastic overlay system, and theinvention allows not just the sensing of a touch, but the sensing of thefunction of the overlay—including its deflection if desired. Wheredesired, an “overlay” can be placed over the screen, or somehow madepart of the screen, where the human operates the overlay function, suchas a lever, and the overlay in turn touches the screen and deforms it toregister the event. and magnitude thereof where desired. In other words,a human actuated contactor, such as a lever, touches the screen.

FIG. 14—“Feeling Screens”

As mentioned above, the invention uniquely may be used to create a“feeling” touch screen. Such a screen utilizes the deformablecharacteristics of an elastic TV screen, such as the plastic screen onthe front of a rear projection television, and allows by the use of thefingers of the user touching this screen at one or more points such asthose at which video data is displayed.

A preferred embodiment of the invention monitors the deformation of thescreen in proportion to the “feel’ of the operator, which essentially isrelated to the x,y,z location of deformation x and y, and the createddeformation in z. Optionally the deformation in the direction of actionin z can also be monitored to provide a vector field.

The principle applications of the feeling portion of the invention areseen as the manipulation of data, using additional inputs or addeddegrees of freedom, than are normally afforded by the use of a mouse,light pens, finger touch, or the like. Allowed is, not only the touchingof multiple fingers, but the direction and degree of force utilizedtherefore.

Other embodiments of the invention envision provision, via a controlledpiezoelectric actuation or the like, a resistive nature to the screen,which presses back against the user as a function of data desired. Inaddition the screen material itself can have a touch tailor made to theapplication. For example to simulate human skin for medical teaching,the screen can be made of a plastic or latex compound which feels likeskin itself, while showing the TV image on its face.

Because the screen can be easily changed, another simulation using theinvention can provide a completely different feel to the user. That isthe screen material, and its feel can be changed. And if desired, itsvisual characteristics too can be changed for example in its lightreflection or transmission characteristics, color, appearance orwhatever. In addition one can have pre treated screens which can bechanged with different printed visuals, or scents, or whatever. Indeedit is envisioned that the optical (laser, projected light) or electronbeam excitation of the screen material provided under programmablecontrol for display purposes, can also be programmed to excite thescreen to cause various smell or touch sensations to be generated inresponse to prerecorded program material or instant input from afar.

One example of a game is a children's petting zoo. In this game, theanimal in question is displayed on the deformable screen of theinvention. The child touches or pets (strokes) the animal. As he/shedoes so, the animal gives off appropriate sounds and moves about as onemight expect. As the video image moves, the child may move his hand(s)to touch it accordingly. The hand input (and possibly voice recognitionas well) is used to activate the movement of the animal. using the touchfeedback modes described above (piezo, vibrational, balloon screens,etc). More than one child or one hand can touch either the one animal,or a group of animals on the screen using the multi-point aspect of theinvention.

Note that one child can also touch an animal located halfway around theworld, via the internet. The image of an animal or other object can betransmitted to the child player, and he can pet it from afar. Via thetouch sensation aspects described above, the child can get feed backfrom his touching and respond accordingly—all with the object touchedgenerated from afar—or from a CD ROM.

FIG. 14 illustrates an embodiment of the invention in which the screenitself is made of bladder like material capable of giving and/orreceiving sensations of touch As shown, the screen 1400 is divided intocells, such as 1410, and 1411 each quasi flat and filled with liquid orgas. The image desired 1420 is projected through the cell. If it isdesired to touch the image instantly visible on the outer surface of thecell 1411 for example (which is preferably transparent but withdiffusive matte finish), the touch is registered by a pressure sensor1430 due to the increase in pressure at the cell in question. If it isdesired that the object represented by the “Image” be comprehended totouch the user, the cell is actuated, via a pump or other mechanism, toput out a pulse or series of pulses or whatever, to return a touchsignal to the users hand (fingers, etc) 1450. As pointed out above, forutmost frequency response in such matters, piezo electric membranes canbe used for this purpose, arranged in as dense a grid as economicallyfeasible.

While D-SIGHT principle of U.S. Pat. No. 4,629,319 is often thepreferred means of distortion measurement, screen displacement ordistortion can alternatively be done via triangulation. stereoscopic orother means. These alternatives are generally best for significantindentations which create slope changes that are too severe for D-SIGHTto give a reliable answer. For example where a latex touch screen of50×35″ dimension was used, the slightest finger pressure created slopechanges which with almost no applied force caused a D-SIGHT baseddeflection analysis to indicate total black at the point inquestion—easily identifying the x y location of the touch, buteffectively beyond the range limit of accurate local zdeflection/distortion measurement.

A grid projection triangulation embodiment has been shown in FIG. 6above. It is understood that rapid scanning of a point triangulationspot across the screen can also be used according to the invention todetermine the location and degree of screen distortion. A Scannercapable of doing this is produced by Hymarc of Ottawa Ontario, underlicense from the Canadian National Research Council. Another is shown inmy pending application incorporated herein by reference, entitled“Controlled Machining”, and issued as U.S. Pat. No. 4,559,684—alsoillustrative of grid projection examples applicable to other embodimentsof this invention.

FIG. 15

An alternative stereoscopic screen deflection determination technique isshown in FIG. 15. A TV screen 1501 is monitored for deflection by astereo pair of cameras 1510 and 1511 which have a field of view of thescreen, and whose outputs are fed to computer 1514 which determines thex, y, and z, position of a point 1520 on the screen by comparing itslocation in each cameras field by known stereo triangulation techniquesemploying differences in the location of the point in question in theimage field of each camera. Note that z is optional, and if not needed,only one camera can suffice.

The question is, what point on the screen has the contrast for thecameras to see? Clearly the point must be manifested to represent thetouch or impact, not the normal video projection. Two possibilities, forexample, are:

Event Causes Indication

In this case, the actual touch of finger 1525 onto the screen, causes aone member 1530 of a composite screen 1500 to press against a second,1531 which then frustrates the internal reflection of near infrared(i.e. non bothersome to human observer) 0.9 micron wavelength radiationfrom IR LED 1540 bouncing between the two members. and causes either alight or dark signal (depending on design) visible to the cameras. Thecameras, at the point of contact then see the point at which thisexception indication occurs, which is stereo triangulated to determineits 3-D position.

The use of the screen itself to carry within it the light needed toregister the indication is unique, and can be done in other ways. Forexample, a network of fiber type channels can go through the screenwhose local transmission or reflection of light would be impacted by thetouch or impact on the screen in question.

Indication always there, camera system looks for differences in instantscreen location or shape vs. stored location or shape.

An alternative is to continually solve for location of the screen, at alarge number of points, and continually subtract the data once obtainedfrom instant data at the same points. Any change any where in the fieldcan then be highlighted, and its x, y, z location determined.

FIG. 16

FIG. 16 illustrates a correction matrix for position and force, usablewith most of the embodiments of the invention. The TV screen 1660 isdivided into “n”×“m” cells 1661, with in the sensor system measuringfield of view, such as that of camera units above used for D-SIGHTimaging of the screen deflection. In a calibration mode, a sequentialexcitation of the screen is made, such as with indenter 1665 driven bycomputer controlled programmable positioner 1670. For each indentationof known amount, the x,y,z, registration is recorded, relative to thecell location and amount of indentation. This calibration table is thenat a later time called from memory to correct a subsequent instant eventposition or amount.

FIG. 17

FIG. 17 illustrates a further screen sensing alternative, in this casenon optical method of screen deflection or distortion measurement,especially valuable for use in impact based gaming. In this case a radarimage is formed of the rear of the screen 1700, using phased array radartransmitter 1710 operating at 1.5 GFIZ. The transmitter is also capableof operating as a receiver, or a separate receiving portion is provided.As such devices are being considered for cars, it is likely prices willgo down sufficiently to allow their use in TVs as here disclosed.

The data rate of the scan is 200 sweeps/second of the screen rear. Theresolution desired is 100×100 over the screen surface in x-y, in orderto sense the impact of a .‘nerf’ or other soft ball thrown at thescreen, in this case a rear projection screen. 2×106 data points persecond are acquired from the screen, using a pulsed mode radar to sensedeflection over short ranges.

Such radar devices in a direct mode can see and if desired tracksequentially the position or velocity of the impacting object itself—asshown in the front projection version of FIG. 17 b. Note that in thiscase the ball hit on the screen is seen from the point of view of itsappearance in the field of the radar sweep, and the degree of recoil ofthe object, which indicates velocity (unless one chooses to monitor thevelocity of the incoming object).

The invention comprehends a screen of a composite that would havestiffeners in it that wouldn't be distracting to the viewer. Forexample, If the stiffeners are square, or shaped such that the rays fromthe projector TV would hit them in a parallel manner, and would not bedeviated, then they would not be apparent. In addition, the screenstiffening portions could purposely be corrugated so as to deflect orrefract projected light to other parts of the room.

Indeed the actual movement of the stiffeners could be measured, ratherthat the real surface of the screen. The stiffeners might be purposelydesigned to reflect or refract light or other suitable radiation to asensing device—or away on impact or touch.

Miscellaneous Points.

Using the invention, one can code an input to the screen by detectingshape of the object used to indent the screen, from distortion image.

In the invention, one can use 3-D glasses on a user, so that a person orobject one is interacting with appears behind screen. e.g. one kicks theball toward a goal but before it gets to the goal, the screen deflectionof the invention senses it going toward the goal and causes a result ofaction of the goalie etc in response.

In the invention one can use stereo cameras in TV looking outward at aplayer (or cameras overhead as shown previously) can see datums onplayer in 3-D so as to tell location relative to displayed image onscreen.

Note one can have games where a player can shoot or throw something atscreen and the object moves or says something in response to where theobject hits the screen.

Note can also box or kung fu kick the screen and register a score. orengender a response from the other player represented on the screen (ortransmitted by TV over the internet or modem or whatever. A multipersongame might be like a shootout at the OK corral, where multiple playersall shoot at once at the screen.

In one embodiment shown herein, the characteristic of the screen isdetermined in its natural state where no input has been made. Thisnatural state is stored, and further then compared sequentially to itsinstant state, with any differences noted and compared to the desiredlocation, force, or direction of the touch, or other screen deformingactivity.

Deflection of the screen can be via electronic means, where an electronbeam or powerful laser excites the screen and deflection is memorized.

One can distinguish both deflection of screen at an arbitrary location,and its x and y location (as well as its z deflection if desired, or onecan see even more detail in sense of distortion of shape of screen—thisgives unambiguous data if screen is moving due to wiggles or wavescaused by impacts or other disturbances, and can allow 5 axis dataincluding trajectory of contact to be determined from the distortion.

For simple determining of where the player is relative to the screencoordinate system, any sort of sensor that can tell where he is can beused. It could be optical, ultrasonic, or radar, or whatever. It isdesired to control the video of the TV as a function of the position ofthe player(s), and what he's doing. This could also include a militaryor police simulation. This is not just a person tracker, but can be ahead tracker, or even to track a gesture, or other complex movement ofthe player as well.

Cameras make an excellent means to track targets on objects, which canbe not just on the human, but something the human interacts with or evensits in, like a riding thing. A combination of targets on all of theabove can be used so that a single camera can deal with multiple objectsthat are needed to be positioned, determined, and tracked. Note that TVcameras and other object tracking devices used with games can also trackpaddles, racquets, balls, etc. used in play.

If the projectile is targeted, or tracked, an automated other person canbe put into play, such as a tennis player, a baseball batter, or otherform of robot that would then hit the ball and return it.

The invention is good for interactive video, using the invention, onecan interact with movies, grab objects unwrap, bend, punch, distort,move around objects, move multiple objects, etc.

The pliable screen could be of cylindrical shape like human standing up,or might be used to project a simulated cadaver for teaching medicalstudents.

A touch pad of the invention, especially used as a multipoint pad canfunction as a mouse or other data input device. Since it can tellsignatures, it can identify the user (via handwriting or other,) and onecan use any object not just ones finger—e.g. a special shaped object,another part of ones anatomy, etc.

The invention can be used for remote interaction over the TV. Indeed canuse the same stereo camera in TV used for target measurement, to look ata player image and transmit. One can touch the screen and get responsevideo or audio as a function of whole experience, for example by a humanfrom far away.

“‘Light’ as used herein, can be electro-magnetic waves at x-ray throughinfra-red wavelengths.

1. A touch interface comprising: a display screen including a frontsurface and a rear surface and adapted to display visually observabledata; a sensor circuit adapted to identify a characteristic of a touchinput on the front surface of the display screen; and a force elementresponsive to the sensor circuit and adapted to excite the displayscreen rear surface by generating a force feedback signal in response tothe characteristic of the touch input.
 2. The touch interface of claim 1wherein: the force feedback signal includes a frequency; and thefrequency is selected as a function of at least the characteristic ofthe touch input.
 3. The touch interface of claim 1 wherein: the forcefeedback signal includes an intensity; and the intensity is selected asa function of at least the characteristic of the touch input.
 4. Thetouch interface of claim 1 wherein: the force feedback signal includes apulse sequence; and the pulse sequence is selected as a function of atleast the characteristic of the touch input.
 5. The touch interface ofclaim 1 wherein the characteristic includes the location of the touchinput.
 6. The touch interface of claim 1 wherein the characteristicincludes at least a component of the force vector of the touch input. 7.The touch interface of claim 1 wherein the touch input includes one of afinger and a thumb in contact with the display screen.
 8. The touchinterface of claim 1 wherein the force feedback signal is directed to aportion of the display screen underlying the touch input.
 9. The touchinterface of claim 1 wherein the force element includes a piezoelectriccrystal.
 10. The touch interface of claim 1 wherein the force elementincludes an air blast generator.
 11. The touch interface of claim 1wherein the force feedback signal is an acoustic wave signal.
 12. Thetouch interface of claim 1 wherein the force element is a first forceelement, the touch interface further including a second force element.13. The touch interface of claim 12 wherein the first and second forceelements correspond to first and second areas of operation on thedisplay screen.
 14. The touch interface of claim 13 wherein the firstand second force elements are operable to feedback data to therespective first and second areas of operation.
 15. A computerimplemented method for providing tactile feedback in response to inputreceived from a user, the method comprising: providing a touch screenincluding a front surface, the touch screen adapted to display visuallyobservable data; providing a force element to actuate the touch screen;detecting a first touch input on the touch screen front surface;determining a characteristic of the first touch input; actuating thetouch screen perpendicular to the touch screen front surface with theforce element to provide a first force feedback signal in response tosaid detecting step; detecting a second touch input; determining acharacteristic of the second touch input different from thecharacteristic of the first touch input; and actuating the touch screenfront surface with a second force feedback signal different from thefirst force feedback signal.
 16. The method according to claim 15wherein: the first force feedback signal includes a first pulsesequence; and the second force feedback signal includes a second pulsesequence different from the first pulse sequence.
 17. The methodaccording to claim 15 wherein the second touch input includes one of afinger and a thumb in contact with the touch screen.
 18. The methodaccording to claim 15 wherein the second force feedback signal isdirected to a portion of the touch screen underlying the second touchinput.
 19. The method according to claim 15 wherein: the first forcefeedback signal indicates a first function selected by the user; and thesecond force feedback signal indicates a second function selected by theuser different from the first function selected by the user.
 20. Themethod according to claim 15 wherein the first touch input and thesecond touch input are simultaneously in contact with the touch screenfront surface.
 21. A touch interface comprising: a display screenincluding a front surface and adapted to display visually observabledata; a sensor circuit adapted to identify the location of at least twosimultaneous contacts on the front surface of the display screen; and aforce element responsive to the sensor circuit and adapted to excite thedisplay screen by generating a force feedback signal in response to atleast one of the at least two simultaneous contacts.
 22. The touchinterface of claim 21 wherein each of the at least two simultaneoustouch contacts includes one of a finger and a thumb in contact with thedisplay screen.
 23. The touch interface of claim 21 wherein the forcefeedback signal is directed to a portion of the display screenunderlying at least one of the at least two simultaneous contacts. 24.The touch interface of claim 21 wherein the force feedback signalincludes a variable frequency.
 25. The touch interface of claim 21wherein the sensor circuit is adapted to determine at least a componentof the force vector of each of the at least two simultaneous contacts.26. The touch interface of claim 21 wherein the force feedback signalincludes a variable intensity.
 27. The touch interface of claim 21wherein the force element includes a piezoelectric crystal.
 28. Thetouch interface of claim 21 wherein the force element includes an airblast generator.
 29. The touch interface of claim 21 wherein the forcefeedback signal is an acoustic wave signal.
 30. A computer implementedmethod for providing tactile feedback in response to input received froma user, the method comprising: providing a touch screen including afront surface, the touch screen adapted to display visually observabledata; identifying a first touch input in a first location on the touchscreen front surface from one of a finger and a thumb; identifying asecond touch input in a second location on the touch screen frontsurface from one of a finger and a thumb, the first touch input and thesecond touch input being simultaneously in contact with the touch screenfront surface, the first location and the second location beingdifferent from one another; and vibrating the touch screen front surfacewith a force feedback signal.
 31. The method according to claim 30wherein the force feedback signal is directed to at least one of thefirst location and the second location.
 32. The method according toclaim 30 further including: determining at least a component of theforce vector corresponding to the first touch input; and determining atleast a component of the force vector corresponding to the second touchinput.
 33. The method according to claim 30 wherein the force feedbacksignal includes a variable frequency.
 34. The method according to claim30 wherein the force feedback signal includes a variable intensity. 35.The method according to claim 30 wherein the force feedback signalincludes a variable pulse width.
 36. The method according to claim 30wherein the force feedback signal is generated by a piezoelectriccrystal.
 37. The method according to claim 30 wherein the force feedbacksignal is generated by an air blast generator.
 38. The method accordingto claim 30 wherein the force feedback signal is an acoustic wavesignal.
 39. The method according to claim 30 wherein: the force feedbacksignal includes a pulse sequence; and the pulse sequence varies as afunction of the location of one of the first touch input and the secondtouch input.
 40. The method according to claim 30 further includingproviding first and second force elements to feedback data to first andsecond portions of the touch screen, respectively.
 41. The methodaccording to claim 40 wherein: the touch screen includes a rear surface;and the first and second force elements are operable to actuate thetouch screen rear surface.
 42. The method according to claim 40 whereinat least one of the first and second force elements includes apiezoelectric crystal.